Measurement & Collapse

I don’t want to spend this issue getting into multiversal shenanigans.

But it’s kind of unavoidable when it comes to the Watcher. Uatu in all his seven-head glory (as in his “seven is greater than fore” head, not that he has seven heads) is a member of a species of “Watchers”— entities whose names explain their jobs a hell of a lot more concisely than I will. Their goals include their namesake, and not much else. You see, the Watchers’ goal has always been to limit their interaction with the “watched”, minimize their own interference (not to be confused with next week’s physics topic), and allow their subjects to maintain the course of their lives uninterrupted. This leaves the species with an abundance of juicy moral dilemmas to dive into.

Our watcher, Uatu, is especially prevalent in the comics because of his assigned jurisdiction in our Solar System, which he observes from his cozy watcher-cave observatory on the moon. What makes our specific toga-donning voyeur unique is the fact that he doesn’t always tend to uphold the Watchers’ oath. Ever since his introduction in the Fantastic Four comics, Uatu has been the special rebel who interferes in the Earth’s affairs to aid our heroes in their fights against evil. Next he’ll start dying his hair.

Now why did I mention multiversal shenanigans? Well if you’ve been involved in the Marvel Cinematic Universe (MCU for short) at all during the pandemic, you’ll know about the animated series “What If…?”, in which Uatu is introduced and used as a centerpiece to tell anthological stories about wacky multiversal variants of the characters we know and love. You’ll be pleased to know he breaks his oath and sticks his nose into those stories every season too; how do people still whine about “comic accuracy”?

While the comics Watchers have the ability to peer across the multiverse at different variations of their designated sector, the show takes the concept a LOT further. I, again, have no interest in humoring the multiverse’s convoluted existence, but the show gives a lot of really good material for me to get into this week’s physics!

Superpositions Don’t Last Forever

You remember last week, when you pressed the “peek without measuring button” and Doctor Manhattan’s glowing hand freaked out and everything fell apart? Well this is that.

As cool and overpowered as superposition feels, our universe’s game developers had to nerf it somehow. That “somehow” is the fragility of superposition: when observed they collapse. But what does it mean to observe a superposition? It doesn’t necessarily mean peeking or looking or watching (see what I did there?) in the literal sense. Our interference, or any interruption in the uncertain superposed state is what snaps it into certainty.

In the realm of quantum computing, which we touched on last week, maintaining a qubit’s superposed state for as long as possible has been a very relevant and very hefty goal. Increasing “coherence time”, the duration of the uninterrupted superposition, has been a primary indicator of the progression of qubit research.

So what about measuring? Well you’ll notice how last week’s simulation had two buttons: “measure” & “peek without measuring”. The funny thing is, regardless of whether you received an error message and a shaky hand behind your choice, both buttons’ outcomes collapsed to one of the two options: 0 or 1. That’s because observation is really just a colloquial explanation of how scientists use tools to measure the state of the superposed particle.

The Multiverse and Collapse

I still don’t want to get into the shenanigans. That said, ‘What If…?’ provides a really compelling analogy with how Uatu’s specific style of “observing” affects a given universe’s outcome. Where other watchers allow their sectors to progress however they would, Uatu’s meddling directly affects the outcome of that multiversal branch, essentially eliminating the other possibilities. That’s exactly what measuring superposition is!

When Uatu summons Captain Carter for the fourteenth time and lets her know that the malfunctioning toaster she’ll encounter in two days is Ultron’s next incarnation, he is personally etching in the outcome that will come to fruition, just as we do when causing superpositions to collapse. (No, that scenario is not canon. Yes, it should be. Yes, I’m accepting job offers, Marvel.)

Just to hammer in this concept, see this week’s simulation! Ask the watcher’s questions and build your own comic, panel by panel with each new outcome!

PREDICT/before you run it

Take a qubit that is definitely UP. Ask 'up or down?' a hundred times and you get UP a hundred times. Now ask it 'left or right?' — what comes back?

Left, every timeRight, every timeA 50/50 coin flipNothing — the question doesn't apply

Lock it in

SIM/watchers-question

The Watcher's question

Watch for the certainty table. Watch it move between rows — and never add up to more than it started with.

he is not looking

Ask the qubit a question

Up or down?Diagonal?Left or right?Just watch — don't ask anythingReset

What can be predicted right now

Up or down?certain:

Diagonal?85%

Left or right?50%

Ask a question

▸What am I looking at?

The circle is every state this qubit can be in. Up is ↑, down is ↓, and the arrow is the qubit itself. There's no phase in play this week, so the picture is flat and complete — nothing is hidden behind it.

The dashed line is the question you asked. A measurement always has a direction: you don't ask "what is it?", you ask "is it this way or that way?" The answer can only ever be one of the two ends of that dashed line, so after asking, the arrow snaps onto it.

Which is why certainty moves around instead of accumulating. Line the arrow up with one question and you've lined it up sideways to another, and sideways means a coin flip. Ask that second question and the arrow snaps again — abandoning everything the first answer told you.

The uncomfortable part: before you asked, there was no answer waiting. A qubit pointing ↑ isn't secretly left or right. It genuinely has no left-or-right answer until a question forces one into existence.

panels 0certain about Up or down

The Watcher’s Dilemma

I promise, this blog isn’t specifically about stoic, baldheaded comic book characters— next week you WILL be seeing both hair and emotions. But while we have this week’s bald guy, Uatu is uniquely compelling because he’s pretty much the most reliably unreliable narrator in fiction. The Watchers have this noble, academic commitment to the sanctity of their sectors’ lives. Like an “Intergalactic Geographic”, they merely chronicle events. How can their findings be pure if they stick their grubby fingers into the people’s business?

But as humans, with empathy, the reader understands where Uatu is coming from. As important as academic purity is, from an objective standpoint these events that are being transcribed are more than lines in a space-encyclopedia. They are experiences that people live up to, that people live through, and that people live beyond. What good is this arbitrary “sanctity” when we diminish people’s value in its name. How do we choose between duty and morality?

I hope you enjoyed Issue 2 as much as I enjoyed making jokes about the fact that Uatu’s name is 75% vowels (truly a Marvel of Jack Kirby’s creative naming). Until next week,

Happy Reading!